William mayer



(No Model.)

W. MAVER, Jr.

BRANCH CIRCUIT FOR QUADRUPLEX TELEGRAPHS. No. 338,996. Patented Mar. 30,1886.

UNrTEn STATES PATENT OFFICE.

\VILLIAM MAVER,JR., OF JERSEY CITY, N. J., ASSIGNOR TO THE BALTI- MOREAND OHIO TELEGRAPH COMPANY, OF BALTIMORE, MD.

BRANCH CIRCUIT FOR QUADRUPLEX TELEGRAPHS.

SPECIFICATION forming part of Letters Patent No. 338,996, dated March30, 1886.

Application tiled October 9, 1885. Serial No. 179,417. (No model.)

To aZZ whom it may concern.-

Be it known that I, WILLIAM MAVER, J r., a citizen of the United States,residing in Jersey City, in the county of Hudson and State of NewJersey, have invented certain new and useful Improvements in Circuitsfor Quadruplex Telegraphs, of which the following is a specification.

In organizing duplex and quadruplex telero graph systems it is sometimesdesired to eX- tend the circuits to include instruments located inneighboring stations-such, for instance, as brokers offices. This may beaccomplished by operating, through a local circuit controlled 1 by oneof the relays of the system, a transmitter which in turn controls theconnections of a circuit including relays for operating the instrumentsin the different sub-stations or lessees offices. Where but one suchoifiee is 2() required, little or no difliculty is experienced; but whenthe number is increased a serious dit'ficulty arises from the change inresistance of the relay-circuit due to the cutting in and out of circuitof the different instruments, on

account of the consequent readjustment of the main-line relay which isrequired.

The object of my invention is to provide means whereby the cutting inand out of cir cuit of the different branch or sub-station 3O relayswill not materially affect the resistance of the circuit in which theyare included.

In carrying out the invention there is applied to one of the main-linerelays a local circuit controlling the operation of a branch-linetransmitter. This transmitter operates to make and break thecircuitconnections of a battery through a series of branch-line relaysin response to the movements of the mainline relay when the latter isactuated by in- 0 coming currents. A key and local relay are alsoincluded in this circuit, and the connections of the latter may be madeand interrupted by this key for the purpose of transmittingsimultaneously upon the main line through the instrumentality of theusual transmitter and upon the branch line in precisely the same manneras when the branch-line transmitter is operated. It is evident thatunder ordinary circumstances the cutting in 0 and out of circuit of thebranch-circuit relays would so vary the resistance in the circuit of thecorresponding battery that a constant adjustment of the local relaywould be required.

To overcome this defect I include in tliebranch circuit an artificialresistance of such amount that the comparative change caused by theinsertion and withdrawal of the relays will not be appreciable. As it isnecessary that the main-line transmitter should not respond to thecompletions and interruptions of the branch circuit, occasioned by themovements of the branch transmitterin response to incoming main-linecurrents, means niustbe provided for maintaining the circuit of thebranch-line battery complete in whatever position this transmitter maybe. For this reason the branch-line transmitter is preferably acontinuity-preserving key, and while its spring is connected through thelocal relay with the battery and its contact-point through the branchrelays to earth, its lever is also connected with the earth through anartificial resistance. This last-named resistance is equivalent to theresistance in the portion of the circuit including the branch relays. Insome 7 5 cases the same artificial resistance may be employed, the leverbeing connected with the earth-conductor between the branch relays andthe first-mentioned artificial resistance.

The accompanying drawing is a diagram illustrating the organization ofthe apparatus and circuits.

Referring to this diagram, L represents a main line of a quadruplexsystem, and R and l? a polar relay and a pole-changing transmitter,respectively, applied thereto in the usual manner. The transmitter isdesigned to be operated by means of currents from a local battery, 0,caused to traverse an electro-magnet, 1). The circuit of the battery 0is con- 9 trolled by the lever of a relay a, included in the branchlinecircuit Z. The line Z leads from one pole of a battery, 0, the otherpole of which is connected with the earth at 9, through the coils of therelay (1 to the contact-spring r of the transmitter P. Thecontact-pointp of this transmitter is connected by a conductor, Z, withone arm of a springjack, J. The other arm of the spring-jack isconnected by a conductor, Z, with the earth at g through a resistance,E. The lever p of the transmitter P is connected with the earth througha conductor, Z at the point 9 An artificial resistance, E is included inthe conductor P. The transmitter P is operated by an electro-magnet, 1f,included in the circuit of a locallbattery, and the circuit-connectionsof this battery are controlled by the operation of the relay R.

Whatever currents are sent to line from the transmitter P do not affectthe polar relay It, for the reason that it is differentially wound orotherwise made unresponsive to outgoing currents; but incoming currentscause the lever of the polar relay to make and break the connections ofthe battery 0, thereby causing the transmitter P to be operated. When inthe position shown in the drawings, the circuit of the battery 0 will becomplete through spring r and stop 9 of the transmitter P, and thus tothe spring-jack J. By operating the key K, which is included inthe lineZ, the circuit of the battery 0 may therefore be made and broken. Asrepresented in the drawing, the circuit is supposed to be open at thekey K, and therefore the lever of the relaya is against its back-stop.By closing the key K, however, the transmitter P will be operated andcurrents sent upon the main line L.

B, B and B" represent three relays,designed to control the connectionsof loop or brokers circuits. It may be desired to include one or more ofthese in the circuit controlled by the key K, or by the polar relay R.For this reason the conductors 1 and 2, which include the coils of therelays, respectively lead to the respective plates 0 and c of switch-pins 0. These pins are designed to be inserted in the spring-jack J,any number at a time. When more than one is placed in the jack, they areplaced with their faces in contact, so that the relays will be includedin series. WVhen, therefore, currents are transmitted over the line I,the relays B, B and B will respond, provided they are included in thecircuit. Suitable keys, f,f and f, are employed for interruptinggthecircuit thus formed, for the purpose of breaking in and transmittingfrom the office containing the relays, as desired.

It is evident that the resistance included in the line will be varied bythe insertion and removal of the various relays B, B, and B Difficultyhas been experienced in maintaining the adjustment of the relay a onthis account. For this reason I insert in the conductors Z and Zrespectively, the resistances E and E and these are of such proportionthat the comparative change made by the insertion of the coils of therelays B, B and B will not materially affect the strength of currentsentto line, and whether the transmitter P be in position to connect theconductor Zwith the conductor Z or with the conductor Z the totalresistance of the circuit of the battery 0 will be approximately thesame on account ofthe high resist ance included in the conductors Zandl. It is evident that the conductor Z might be led back. to theconductor Z at a point above the resistance E and in this manner theresistance E might be dispensed with.

I claim as my invention 1. The combination, substantially as hereinbefore set forth, of a relay, a transmitter controlled thereby, abattery the circuit-connections of which are controlled by the movementsof said transmitter, an artificial resistance included in the saidcircuit, a series of relays and means for including the same in saidcircuit between the transmitter and the earth.

2. The combination, substantially as hereinbefore set forth, with themain line of a telegraph system and a relay included therein, of aseries of relays for controlling branch circuits, a battery, acontinuously-preserving transmitter for controlling the connections ofsaid battery, an artificial resistance through which the circuit of saidbattery is completed, and means for inserting more or less of saidseries of relays in the circuit of said battery.

In testimony whereof I have hereunto sub scribed my name this 8th day ofOctober, A. D. 1885. v

WILLIAM MAVER, JR. Witnesses:

DANL. W. EDGECOMB, CHARLES A. TERRY.

